Aireal 20mm front hub rebuild

[Speshul K]

I've just bought a second hand Aireal front hub, it's the model without the QR/20mm switch system. I haven't had a chance to fully check it out myself as I loaned it out straight away but I've been informed that the bearings are shot. What's involved in replacing these.... can't be hard right..... pop out bearings..... show bearing to bearing shop and get some hot new ones..... pop back in???

If anyone has replaced the bearing on the Aireal hubs before can you let me know which ones you used...?? I know Roasty and tripmitz have done theirs.... Also if anyone has or knows where to get an exploded diagram of the hub I'll pretty much love you for ever.

Here is the culprit

Cheers

 

[wooley_89]

are they RST alfalfas? they were wicked, untill i broke them lol.

um.... and about the exploded view have you looked on the arieal website? or phoned them up?

 

[Speshul K]

are they RST alfalfas? they were wicked, untill i broke them lol.

um.... and about the exploded view have you looked on the arieal website? or phoned them up?

Not sure about the forks, that photo isn't from my bike... they are RST though as far as I know....

Yeah I'm still looking at the Aireal site but have to be very sneaky because I'm still at work...... and therefor probably should be working...

 

[udi]

Seven - the bearings are number 6904 and the sealing type you are after is 2RS obviously.. rubber seals on both sides.

OD: 37mm, ID: 20mm, Width: 9mm

I buy my bearings from a shop in mansfield called mini-bearings, their service is excellent and the bearings are too - I have purchased from them many times. Fast postage too if you want to order them online.

http://www.minibearings.com.au/cgi-bin/item_info.pl?product=6904-2RS&alphafile=B=post

But any bearing shop should be able to hook you up with what you need.

I haven't pulled apart an Aireal, so can't tell you exactly how - but usally the 20mm hubs have endcaps that are either just pressed in, or are held in by a circlip. If there's a circlip, just remove that and the endcaps will pop out, if there's no clip, the endcaps should just slide out with a bit of effort. Good luck.

-Udi

 

[Speshul K]

Yeah I found that on the site too, cheers...

The nice lady is sending me some diagrams and a run down... even though it does sounds very simple....

 

[Red Rocket]

There is no circlip on aireal switch system hubs, just a friction fit within the tolerances of the two parties.


I used a flat head screw driver to gently pop out my seals, though the bearings are a bit more of a problem. I.e. tighter fit.

Whilst you CAN go for rubber sealed tpye bearings again, there is already the primary seal kit, so you don't really need the protection of the full rubber sealed bearing type, rather the tin/rubber type. Whilst them tin/rubber seal type is a couple of dollars more expensive, and offers a little less protection ?marignal difference unless imersed in crap) they spin MUCH faster and have dramatically reduced friction. These are the bearings I would choose.

Anyway it is a very common bearing size and you should be able to pick them up very easily at your local bearing place.


Oh and just a word of warning, if and when you take out the bearings, there will be a little tube in between the two bearings and in the centre of the hub. The 20mm through axle goes through this. I know people probably wouldn't be silly enough to take something out of a hub, but this tube prevents prevents the bearings incurring any sort of side loading when tightening up the 20mm axle encaps, so whatever enybody does, do NOT ever take it out, or you will be up for new bearings again within say a month or two.

 

[tripmitz]

hey,

you can knock out the end caps on the hub from the inside. ie use a tool with a little lip, insert from otherside and line up the tool with the lip between the bearing and endcap of the hub and knock the endcap out. They are just pressed in with no circlip. Then you'll have to have a go at knocking out the bearings. At least that's what i remember! It was a while ago i changed the bearings.

I think we just used the old bearings themselves and/or the endcaps in a vice to press in the new bearings.

Certainly the bearings supplied with the hub destroyed themselves a bit too quickly for my liking. Although thats the way it goes with replaceable parts. Any bearing supply store will have those bearings, i sourced mine from a bearing store in West Melbourne.

 

[udi]

Whilst you CAN go for rubber sealed tpye bearings again, there is already the primary seal kit, so you don't really need the protection of the full rubber sealed bearing type, rather the tin/rubber type. Whilst them tin/rubber seal type is a couple of dollars more expensive, and offers a little less protection ?marignal difference unless imersed in crap) they spin MUCH faster and have dramatically reduced friction. These are the bearings I would choose.

tin/rubber? what the...

I am guessing you are reffering to metal-shielded bearings, and no I wouldn't touch them for hub bearings. If you consider the rotational speed of bearings in a hub (not very fast) and the influence of them on overall speed and rolling resistance, it is a pointless exercise - that would merely shorten the life of the bearings.

Having owned my fair share of highend hubs (and el-cheapo ones too) I can say without a doubt that at least a small amount of water CAN very easily make it past the endcap seals. It's not uncommon that fine dust will make it through as well.

So you'd be plain stupid to not opt for proper rubber sealed bearings. I go one step further even - pop the seals, and pack them with some good lithium grease before install.

This isn't roadie racing - it's DH.

-Udi